I hope I don't sound nosy but does your fiance have anything like Crohn's Disease or Ulcerative Colitis? I know you have to keep yourself hydrated with these conditions.

Well, I don't have a better answer than the others but if he has a condition which causes this, go to HealingWell.com and click on Community. They have a board there where you can post your question. They have the boards arranged according to the type of disease or problem. There is one for diabetes for sure. Even if he doesn't have Crohn's, ask the question on that board. It stays almost as busy as this place does! Someone will get back to you very soon! HTH
-Ginger
GingerinAL@aol.com